GC.ReRegisterForFinalize(Object) Método

Definição

Solicita que o sistema chame o finalizador do objeto especificado para o qual SuppressFinalize(Object) foi chamado anteriormente.Requests that the system call the finalizer for the specified object for which SuppressFinalize(Object) has previously been called.

public:
 static void ReRegisterForFinalize(System::Object ^ obj);
public static void ReRegisterForFinalize (object obj);
static member ReRegisterForFinalize : obj -> unit
Public Shared Sub ReRegisterForFinalize (obj As Object)

Parâmetros

obj
Object

O objeto para o qual um finalizador deve ser chamado.The object that a finalizer must be called for.

Exceções

obj é null.obj is null.

Exemplos

O exemplo a seguir demonstra como usar o método ReRegisterForFinalize para finalizar um objeto uma segunda vez após a coleta de lixo.The following example demonstrates how to use the ReRegisterForFinalize method to finalize an object a second time after garbage collection.

using namespace System;
ref class MyFinalizeObject
{
public:
   static MyFinalizeObject^ currentInstance = nullptr;

private:
   bool hasFinalized;

public:
   MyFinalizeObject()
   {
      hasFinalized = false;
   }

   ~MyFinalizeObject()
   {
      if ( hasFinalized == false )
      {
         Console::WriteLine( "First finalization" );
         
         // Put this object back into a root by creating
         // a reference to it.
         MyFinalizeObject::currentInstance = this;
         
         // Indicate that this instance has finalized once.
         hasFinalized = true;
         
         // Place a reference to this object back in the
         // finalization queue.
         GC::ReRegisterForFinalize( this );
      }
      else
      {
         Console::WriteLine( "Second finalization" );
      }
   }

};

int main()
{
   
   // Create a MyFinalizeObject.
   MyFinalizeObject^ mfo = gcnew MyFinalizeObject;
   
   // Release the reference to mfo.
   mfo = nullptr;
   
   // Force a garbage collection.
   GC::Collect();
   
   // At this point mfo will have gone through the first Finalize.
   // There should now be a reference to mfo in the static
   // MyFinalizeObject::currentInstance field.  Setting this value
   // to 0 and forcing another garbage collection will now
   // cause the object to Finalize permanently.
   MyFinalizeObject::currentInstance = nullptr;
   GC::Collect();
}

using System;

namespace ReRegisterForFinalizeExample
{
    class MyMainClass
    {
        static void Main()
        {
            // Create a MyFinalizeObject.
            MyFinalizeObject mfo = new MyFinalizeObject();

            // Release the reference to mfo.
            mfo = null;

            // Force a garbage collection.
            GC.Collect();

            // At this point mfo will have gone through the first Finalize.
            // There should now be a reference to mfo in the static
            // MyFinalizeObject.currentInstance field.  Setting this value
            // to null and forcing another garbage collection will now
            // cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = null;
            GC.Collect();
        }
    }

    class MyFinalizeObject
    {
        public static MyFinalizeObject currentInstance = null;
        private bool hasFinalized = false;

        ~MyFinalizeObject()
        {
            if(hasFinalized == false)
            {
                Console.WriteLine("First finalization");
            
                // Put this object back into a root by creating
                // a reference to it.
                MyFinalizeObject.currentInstance = this;
            
                // Indicate that this instance has finalized once.
                hasFinalized = true;

                // Place a reference to this object back in the
                // finalization queue.
                GC.ReRegisterForFinalize(this);
            }
            else
            {
                Console.WriteLine("Second finalization");
            }
        }
    }
}
Namespace ReRegisterForFinalizeExample
    Class MyMainClass
        Shared Sub Main()
            'Create a MyFinalizeObject.
            Dim mfo As New MyFinalizeObject()

            'Release the reference to mfo.
            mfo = Nothing

            'Force a garbage collection.
            GC.Collect()

            'At this point mfo will have gone through the first Finalize.
            'There should now be a reference to mfo in the static
            'MyFinalizeObject.currentInstance field.  Setting this value
            'to null and forcing another garbage collection will now
            'cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = Nothing
            GC.Collect()
        End Sub
    End Class

    Class MyFinalizeObject
        Public Shared currentInstance As MyFinalizeObject = Nothing
        Private hasFinalized As Boolean = False

        Protected Overrides Sub Finalize()
            If hasFinalized = False Then
                Console.WriteLine("First finalization")

                'Put this object back into a root by creating
                'a reference to it.
                MyFinalizeObject.currentInstance = Me

                'Indicate that this instance has finalized once.
                hasFinalized = True

                'Place a reference to this object back in the
                'finalization queue.
                GC.ReRegisterForFinalize(Me)
            Else
                Console.WriteLine("Second finalization")
            End If
            MyBase.Finalize()
        End Sub
    End Class
End Namespace

Comentários

O método ReRegisterForFinalize adiciona o parâmetro obj à lista de objetos que solicitam a finalização antes que o coletor de lixo libere o objeto.The ReRegisterForFinalize method adds the obj parameter to the list of objects that request finalization before the garbage collector frees the object. O parâmetro obj deve ser o chamador deste método.The obj parameter must be the caller of this method.

Chamar o método ReRegisterForFinalize não garante que o coletor de lixo chamará o finalizador de um objeto.Calling the ReRegisterForFinalize method does not guarantee that the garbage collector will call an object's finalizer.

Por padrão, todos os objetos que implementam finalizadores são adicionados à lista de objetos que exigem finalização; no entanto, um objeto pode já ter sido finalizado ou pode ter desabilitado a finalização chamando o método SuppressFinalize.By default, all objects that implement finalizers are added to the list of objects that require finalization; however, an object might have already been finalized or might have disabled finalization by calling the SuppressFinalize method.

Um finalizador pode usar esse método para se ressuscitar ou um objeto referenciado por ele.A finalizer can use this method to resurrect itself or an object that it references.

Aplica-se a

Veja também